I'm going to say... member. As in ember. But there are probably multiple answers. And embers don't have to be from wood.
EDIT: Do you mean the action of burning something, or the adjective of something being on fire? If the former, it could be graze. As in raze. As in 'Raze to the ground'.
Holy shit, I was joking. I feel pleased with that. Funnily enough, I did almost say a centipide. OANST seems to have covered that for me with a similar thing, anyway.
__________________
A man walks into a zoo. There's nothing there but one dog. It was a shih-tzu.
I never was, am always to be,
No one ever saw me, nor ever will,
And yet I am the confidence of all
To live and breathe on this terrestrial ball.
What am I?
i'm fairly sure no one will guess this in the next 3 posts.